I had mast & immediate implant recon in June 2011 & I have never been pain free since, its not pain that I take anything for ....except when I had a bleed behind the implant. The bleed made me feel like my chest was about to explode because it had basically expanded my skin another 200ml from behind the implant......anyway I have had to return to the physio because of terrible pain that wasn't going away after the surgery to fix the bleed in november 2012. It was/is in my shoulder & the muscle over the implant, I had shocking restriction of movement & since having some more physio it is easing slowly, there is a bit of contracture happening too (post rads) so I hope this helps with that as well. I would get to your post surgery physio & see if they can help.
Carmel